Backticks

Backticks usage

There are many examples where backticks are used inside a query but for many it's still unclear when or where to use backticks ```sql`.

Backticks are mainly used to prevent an error called "MySQL reserved word". When making a table in PHPmyAdmin you are sometimes faced with a warning or alert that you are using a "MySQL reserved word".

For example when you create a table with a column named "group" you get a warning. This is because you can make the following query:

SELECT student_name, AVG(test_score) FROM student GROUP BY group

To make sure you don't get an error in your query you have to use backticks so your query becomes:

SELECT student_name, AVG(test_score) FROM student GROUP BY `group`

Table

Not only column names can be surrounded by backticks, but also table names. For example when you need to JOIN multiple tables.

SELECT `users`.`username`, `groups`.`group` FROM `users`

Easier to read

As you can see using backticks around table and column names also make the query easier to read.

For example when you are used to write querys all in lower case:

select student_name, AVG(test_score) from student group by group
select `student_name`, AVG(`test_score`) from `student` group by `group`

Please see the MySQL Manual page entitled Keywords and Reserved Words (opens new window). The ones with an (R) are Reserved Words. The others are merely Keywords. The Reserved require special caution.